A descendant of AbstractStructureFixer that can fix attachment errors in R-group definition members.
Errors are fixed according to the corresponding R-atoms, provided that they have the same number of bonds
with the same bond types.

R-group definition members are fixed as follows:

superfluous attachment points are removed;

missing attachment points are added if their positions can be determined unambiguously (with respect to
valences);

the type of attachment bonds are set according to the bonds of the R-atoms.